This invention relates to towing vehicles and more particularly to a wheel retainer blade for the vehicle support member of wheel lift apparatus for supporting the rear portion of the wheels or tires of a vehicle to be lifted or towed.
Because of the large amount of plastic material used on the front and rear portions and bumpers of recent model automobiles, developments in the art of lifting and towing disabled vehicles by a towing vehicle have been directed toward what is known in the art as "wheel lift" devices, which engage and lift the front or rear tires of a disabled vehicle. Examples of towing apparatus incorporating such devices are illustrated in Wagner U. S. Pat. No. 3,182,829; Bubik U.S. Pat. No. 3,897,879; Cannon Jr. et al U. S. Pat. No. 4,451,193; Brown U.S. Pat. No. 4,473,334; Porter Sr. et al U.S. Pat. No. 4,573,857; Hamman U.S. Pat. No. 4,634,337; Bubik U.S. Pat. No. 4,637,623 and Holmes et. al U.S. Pat. No. 4,679,978. As disclosed in each of these patents the tires of a disabled vehicle are disposed within the well of some form of cradle, the cradle having members which engage and support the front and rear of the tires carried therein.
The wheel supporting cradles generally have a fork of a substantially U-shaped configuration in plan, the legs of the cradle opening either inwardly, outwardly or rearwardly. In the latter instance the open position is closed by a retaining member subsequent to the tire being disposed within the well, the retaining member engaging the rear of the tire. In the former cases, the rear of the tire is engaged by an arm, commonly known in the art as an "L" arm since it has that configuration, and such arm may have an upstanding arcuate contour conforming somewhat to the shape of the tire so as to provide greater support by the larger surface contact with the tire. Examples of the former "L" arm configurations are illustrated in at least the aforesaid Porter et al and Holmes patent, while examples of the latter "L" arm configurations are illustrated in at least Wagner and the Bubik '623 patents.
The front of the tire generally merely rests on a ramp either formed on the front leg of the U-shaped cradle, as in Cannon et al and Porter et al, or formed on the rear of a laterally extending cross arm or tow bar which carries the "L" arms at its extremities, such as in Bubik '623 and Holmes. In Wagner, both the front and rear support for the tires is provided by spaced apart arcuate shaped plates or feet which are connected together by chains so that both the front and rear of the tire is engaged by the greater surface contact provided by these contoured feet. However, in Wagner the feet on both sides of the vehicle are carried by a respective arm depending downwardly from a frame supported above the vehicle to be towed, and the entire wheel lift apparatus is difficult to utilize effectively. This is one reason the art has developed in the direction of engaging the tires with a wheel lift device which enters from beneath the disabled vehicle.
When a disabled vehicle is being towed, it is highly desirable that the tires rest securely within the cradle so that the momentum of the disabled vehicle does not result in the tires rolling and disengaging from the cradle when the towing vehicle accelerates or stops. On acceleration, the disabled vehicle and the tires tend to surge rearwardly, but upon stopping of the towing vehicle, the disabled vehicle and the tires tend to surge forwardly. Accordingly, it is highly desirable to have enlarged wheel engaging feet at the front and rear of the cradle.
One of the problems presented when engaging the tires from beneath the vehicle is that modern automobiles have a low configuration, that is, they are built low to the ground and the bodies thereof have low ground clearance and small clearance between the tire wells and the tires. Thus, if the cradle has enlarged feet, the low clearance prevents the feet from entering beneath the automobile from, for example, the front of the vehicle. If a large foot is desirable to support the front of the tire of the disabled vehicle, then the prior art, as exemplified by the aforesaid Porter et al patent, has not utilized a foot at the rear of the tire but has provided means for rotating the rear support of the cradle outwardly from beneath the vehicle. However, even here if the disabled vehicle has a very low ground clearance at the front, the upstanding foot will not slip beneath the body of the vehicle into the tire engaging position. If a large foot is desired to support the rear of the disabled tire, the foot may be rotated inwardly from the outboard side of the vehicle, as exemplified by the Bubik ' 623 patent. However, as illustrated in that patent, the front support is merely a ramp on the cross bar or the like since a large foot for supporting the front of the tire will not enter beneath the low ground clearance front end of late model vehicles.
In copending U.S. patent application Ser. No. 07/183,044 filed on Apr. 19, 1988, by Walter G. Lock, one of the coinventors herein and assigned to Holmes International Inc., the same assignee of the present application, there is disclosed a pivotably foldable ramp juxtaposed adjacent to the fixed ramp at the front of the cradle, the foldable ramp providing an extension of the fixed ramp, and thus an enlarged foot at the front, when in an operative position, yet may be pivotably folded to an inoperative position which permits the support member on which it is mounted to enter beneath low ground clearance vehicles without presenting an obstacle thereto.
However, as aforesaid, it also desirable to have an enlarged foot for supporting the rear surface of the wheel or tire of the vehicle to be towed. Although the Bubik '623 patent does disclose an enlarged upstanding foot or blade, it requires that the arm to which the foot is attached be rotated a substantial amount for the foot to be received behind the rear of the tire, and it must then be lifted in order to adjust the arm longitudinally to engage the rear surface of the tire with the blade. When positioning the support arm it is more natural to merely slide the arm forwardly to engage the blade against the rear surface of the wheel. However, with the small wheel well clearances of recent automobiles this cannot be accomplished with the prior art blades such as that illustrated in Bubik '623 since the blade provides an obstacle for substantial movement of the arm so that it must be rotated to position the blade to closely adjacent the rear surface of the wheel. Additionally, apparatus such as disclosed in Bubik '623 may not be used when the tire of the vehicle to be towed is immediately adjacent to a curb or the like unless the vehicle has a high wheel well clearance or else the top of the blade when rotated from the higher level of the curb will engage the body of the vehicle. Furthermore, when a disabled vehicle, such as one involved in an accident, has flats in one or more of the tires which are to be lifted, the vehicle must first be winched to dispose the tires properly for lifting by the cradles. In such instances, because of the flats, the tires are spread wide at the bottom so that if the arm of the cradle were adjusted to its full extent, either the crotch of the cradle would still be too small to straddle and grip the tire, or even if the cradle could straddle and grip the tire while on the ground, once the towing bar is lifted, the tire would slip through the cradle between the front and rear supports. Thus, it is current practice in the art to use the tow bar itself to lift the vehicle off the ground and then place blocks beneath the tires. Thereafter the "L" arms are adjusted to the required size of the tire which is then positioned and supported by the cradle. The tow bar is then lifted further and the blocks are removed. Not only is this time consuming, but it can also cause damage to the vehicle and be unsafe.